Diminished chords are more common than most people think. They do sound a little other-worldly out of context, but they are very frequently used in harmonic progressions, for reasons I'll go into in a second. If you're not sure what a diminished chord sounds like, the intro to Ghost Town by the Specials (which got to number one in the UK charts in the summer of 1981 - wow, that makes me feel old!) is the best example I know. It has a series of six consecutive diminished chords, each a semitone higher than the previous one.
I'll explain what a diminished chord actually is before I tell you why it's useful. A proper diminished chord (strictly, I should specify that I'm talking about a "diminished seventh chord") has four notes in it, and each is a minor third above the one below. To create one on the piano, pick any note, count three keys to the right (not counting the one you started with, but counting both white and black keys) and play that note, then repeat. By the fourth repeat you should have reached the note an octave above your starting note. Here are all the diminished chords:
If you've ever done any instrumental exams from Grade 5 upwards, you'll probably be well aware that there are only actually THREE different diminished chords (the Grade 5+ ABRSM exams ask you to play diminished arpeggios). If you haven't, look at the chords above, and it will be obvious. The chords in the first line (C dim, C# dim and D dim) all have different notes, but the others all have the same notes as the ones in the first line, just in a different order. And unlike most other chords, which sound recognisably different if a different note is at the bottom, diminished chords have a sort of uncertain quality, which means that they sound more or less the same whichever note's on the bottom.
This uncertain quality means that composers often use this chord to suggest such concepts as change, distress, restlessness - and of course supernatural elements (as in Ghost Town). One of the reasons for the uncertain quality is that there are very many possible ways in which the chord's dissonances can resolve. In a piece that uses standard classical harmony, there are fewer options than you might expect when it comes to which chord sounds natural after the one you've just had. (That's a terrible sentence, but hopefully you know what I mean!) However, with a diminished chord, there are a LOT of options, so they can be very useful for creating variety, or changing the key altogether. For example, here are a few chords that could follow D dim:
If you play them on the piano, you'll realise that the music would go in a totally different direction each time.
When singing diminished chords, there are a couple of things that are useful to bear in mind. These chords come up in two different ways in a choral context - either you're singing one note of a diminished chord (and the rest of the choir are singing the other notes), or you're singing a vocal line which has a few notes from a diminished arpeggio in it. The former is much more common - in the latter case, the main thing to remember (as always with minor thirds) is that the interval is usually smaller than you think, so if you're coming DOWN a diminished arpeggio, think "Eek! Descending minor thirds!" and hopefully you will channel our ex-choral director and remember not to go flat. Going UP the arpeggio isn't quite as hard, but it's still worth thinking about the tuning.
If you're singing one note of the chord, the most difficult thing is actually coming in on the right one. It's not so bad if the diminished chord only happens when you actually sing it, but there are quite a few examples like the end of the Confutatis Maledictis movement of Mozart's Requiem. I'm talking about the "oro supplex" bit (starting at 1:24 in the linked video). It's probably not too hard for the basses, but I know that the first few times I sang the alto part, I had to really concentrate in order to come in on the right note at the start of each of those four phrases. It's almost impossible to reliably pick it out of the chord that's heard in the first two beats (when the basses come in) - I could easily pick a note that FITS, but if I'm not thinking about it properly, it's quite easy to come in on the tenor note instead of the alto one. I can get it quite easily now, but that's mainly through muscle memory. (I notice he fixes it so the sops just have to remember the same note each time - sensible chap!)
No comments:
Post a Comment